<template>
  <div class="my-tag">
    <input
      v-if="isEdit"
      v-focus
      ref="inp"
      class="input"
      type="text"
      placeholder="输入标签"
      :value="value"
      @blur="isEdit = false"
      @keyup.enter="handleEnter"
    />
    <div
      v-else
      @dblclick="handleClick"
      class="text">
      {{value}}
    </div>
  </div>
</template>

<script>
export default {
    props: {
        value: String
    },
    data () {
        return {
            isEdit: false
        }
    },
    methods: {
        handleClick() {
            //双击后，切换到显示状态 (异步dom更新)
            this.isEdit = true
            //等dom更新完了，再获取焦点
            /* this.$nextTick(() => {
                //立刻获取焦点
                this.$refs.inp.focus()
            }) */
        },
        handleEnter (e) {
            //非空处理
            if (e.target.value.trim() === '') return alert('标签内容不能为空')

            //console.log('回车了')
            //子传父，将回车时，输入框的内容提交给父组件更新
            //由于父组件是v-model，触发事件，需要触发input事件
            this.$emit('input', e.target.value)
            //提交完毕，关闭输入状态
            this.isEdit = false
        }
    }
};
</script>

<style lang="less" scoped>
.my-tag {
    cursor: pointer;
    .input {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      width: 100px;
      height: 40px;
      box-sizing: border-box;
      padding: 10px;
      color: #666;
      &::placeholder {
        color: #666;
      }
    }
  }
</style>